Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)
Jeudi 3 juin 2010
Amphi 206 (Cœur d’Ecole) à 14h
Role of three HMA transporters in metal allocation and detoxification in Arabidopsis
Laboratoire des Echanges Membranaires et Signalisation – CEA Cadarache
The P1B-ATPase subfamily in Arabidopsis comprises height members (HMA1-8) predicted to be involved in the translocation of monovalent, Cu+/Ag+, or divalent, Zn2+/Cd2+/Pb2+/Co2+, cations. While the monovalent transporters are present in all living organisms, divalent transporters are absent in animals. Our work as focused on the role of HMA1, HMA3 and HMA4 all predicted to be divalent cation transporters. In planta these three transporters are located to different intracellular membranes and play different roles. HMA1 is the most atypical member of this family since it lacks the canonical MBDs (Metal Binding Domains) present in all other members of the family. We have shown that HMA1 is located to the chloroplast envelope and participates in copper influx into the chloroplast for its delivery to detoxifying enzymes. The two others, HMA3 and HMA4, are involved in Zn homeostasis. HMA4 is located at the plasma membrane and participates in Zn and Cd translocation from the roots to the shoot while HMA3 is at the tonoplast and drives vacuolar sequestration of Zn and Cd. Further insights in the characterization of these transporters will be discussed.
Contact : Rémy Gibrat